diff --git a/examples/audioExamples/injectorLoadTest.js b/examples/audioExamples/injectorLoadTest.js
new file mode 100644
index 0000000000..3df2d873c7
--- /dev/null
+++ b/examples/audioExamples/injectorLoadTest.js
@@ -0,0 +1,94 @@
+//
+//  injectorLoadTest.js
+//  audio
+//
+//  Created by Eric Levin 2/1/2016
+//  Copyright 2016 High Fidelity, Inc.
+
+//  This  script tests what happens when many audio injectors are created and played
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+
+
+Script.include("../libraries/utils.js");
+
+
+var numSoundsToPlayPerBatch = 35 // Number of simultaneously playing sounds
+var numSoundsPlaying = 0;
+var timeBetweenBatch = 30000;
+// A green box represents an injector that is playing
+
+var basePosition = {
+    x: 0,
+    y: 0,
+    z: 0
+};
+
+var soundBoxes = [];
+
+var testSound = SoundCache.getSound("https://s3-us-west-1.amazonaws.com/hifi-content/eric/Sounds/dove.wav");
+var totalInjectors = 0;
+var clipDuration;
+
+if(!testSound.downloaded) {
+
+    print("SOUND IS NOT READY YET")
+    testSound.ready.connect(function() {
+        playSounds();
+        clipDuration = testSound.duration;
+    });
+} else {
+    // otherwise play sounds right away
+    playSounds();
+    clipDuration = testSound.duration;
+}
+
+function playSounds() {
+    print("PLAY SOUNDS!")
+    for (var i = 0; i < numSoundsToPlayPerBatch; i++) {
+        playSound();
+    } 
+
+    Script.setTimeout(function() {
+        numSoundsPlaying = 0;
+    }, clipDuration);
+    print("EBL Total Number of Injectors: " + totalInjectors);
+    
+    Script.setTimeout(function() {
+        playSounds();
+    }, timeBetweenBatch);    
+}
+
+
+function playSound() {
+    var position = Vec3.sum(basePosition, {x: randFloat(-.1, .1), y: randFloat(-1, 1), z: randFloat(-3, -.1)});
+    var injector = Audio.playSound(testSound, {
+        position: position,
+        volume: 0.2
+    });
+
+    numSoundsPlaying++;
+    print("NUM SOUNDS PLAYING: " + numSoundsPlaying);
+    print("*******************************************");
+    print("INJECTOR VALUE: ")
+    print(JSON.stringify(injector));
+    totalInjectors++;
+
+    var soundBox = Entities.addEntity({
+        type: "Box",
+        name: "Debug Sound Box",
+        color: {red: 200, green: 10, blue: 200},
+        dimensions: {x: 0.1, y: 0.1, z: 0.1},
+        position: position
+    });
+
+    soundBoxes.push(soundBox);
+}
+
+function cleanup() {
+    soundBoxes.forEach( function(soundBox) {
+        Entities.deleteEntity(soundBox);
+    });
+}
+
+Script.scriptEnding.connect(cleanup);
\ No newline at end of file
diff --git a/examples/html/entityProperties.html b/examples/html/entityProperties.html
index fd98dcea2f..67ed261b5d 100644
--- a/examples/html/entityProperties.html
+++ b/examples/html/entityProperties.html
@@ -1237,9 +1237,9 @@
         <div class="property">
             <div class="label">Position</div>
             <div class="value">
-                <div class="input-area ">X<input class="coord" type='number' id="property-pos-x" step="0.1"><div class="prop-x"></div></div>
-                <div class="input-area ">Y<input class="coord" type='number' id="property-pos-y" step="0.1"><div class="prop-y"></div></div>
-                <div class="input-area ">Z<input class="coord" type='number' id="property-pos-z" step="0.1"><div class="prop-z"></div></div>
+                <div class="input-area ">X<input class="coord" type='number' id="property-pos-x"><div class="prop-x"></div></div>
+                <div class="input-area ">Y<input class="coord" type='number' id="property-pos-y"><div class="prop-y"></div></div>
+                <div class="input-area ">Z<input class="coord" type='number' id="property-pos-z" ><div class="prop-z"></div></div>
                 <div>
                     <input type="button" id="move-selection-to-grid" value="Selection to Grid">
                     <input type="button" id="move-all-to-grid" value="All to Grid">
diff --git a/examples/utilities/tools/render/debug.js b/examples/utilities/tools/render/debug.js
index f195c607a4..eba967491b 100644
--- a/examples/utilities/tools/render/debug.js
+++ b/examples/utilities/tools/render/debug.js
@@ -14,9 +14,6 @@ Render.RenderShadowTask.enabled = true;
 var RDT = Render.RenderDeferredTask;
 RDT.AmbientOcclusion.enabled = true;
 RDT.DebugDeferredBuffer.enabled = false;
-["DrawOpaqueDeferred", "DrawTransparentDeferred", "DrawOverlay3DOpaque", "DrawOverlay3DTransparent"]
-    .map(function(name) { return RDT[name]; })
-	.forEach(function(job) { job.maxDrawn = job.numDrawn; });
 
 // Set up the qml ui
 var qml = Script.resolvePath('main.qml');
@@ -39,4 +36,4 @@ function setDebugBufferSize(x) {
     Render.RenderDeferredTask.DebugDeferredBuffer.size = {x: x, y: -1, z: 1, w: 1};
 }
 
-Script.scriptEnding.connect(function() { Render.fromJSON(oldConfig); } );
+Script.scriptEnding.connect(function() { Render.load(oldConfig); } );
diff --git a/examples/utilities/tools/render/main.qml b/examples/utilities/tools/render/main.qml
index 9e825ad4df..22f263b2d0 100644
--- a/examples/utilities/tools/render/main.qml
+++ b/examples/utilities/tools/render/main.qml
@@ -12,98 +12,109 @@ import QtQuick 2.5
 import QtQuick.Controls 1.4
 
 Column {
-    spacing: 8
-
-    Repeater {
-        model: [ "Opaque:DrawOpaqueDeferred", "Transparent:DrawTransparentDeferred",
-                "Opaque Overlays:DrawOverlay3DOpaque", "Transparent Overlays:DrawOverlay3DTransparent" ]
-        ConfigSlider {
-            label: qsTr(modelData.split(":")[0])
-            integral: true
-            config: Render.getConfig(modelData.split(":")[1])
-            property: "maxDrawn"
-            max: config.numDrawn
-        }
-    }
-
-    Row {
-        CheckBox {
-            text: qsTr("Display Status")
-            onCheckedChanged: { Render.getConfig("DrawStatus").showDisplay = checked }
-        }
-        CheckBox {
-            text: qsTr("Network/Physics Status")
-            onCheckedChanged: { Render.getConfig("DrawStatus").showNetwork = checked }
-        }
-    }
-
-    ConfigSlider {
-        label: qsTr("Tone Mapping Exposure")
-        config: Render.getConfig("ToneMapping")
-        property: "exposure"
-        min: -10; max: 10
+    id: root
+    spacing: 16
+    Switch {
+        checked: true
+        onClicked: ui.visible = checked
     }
 
     Column {
-        id: ambientOcclusion
-        property var config: Render.getConfig("AmbientOcclusion")
+        id: ui
+        spacing: 8
 
-        Label { text: qsTr("Ambient Occlusion") }
-        // TODO: Add gpuTimer
-        CheckBox { text: qsTr("Dithering"); checked: ambientOcclusion.config.ditheringEnabled }
         Repeater {
-            model: [
-                "Resolution Level:resolutionLevel:4",
-                "Obscurance Level:obscuranceLevel:1",
-                "Radius:radius:2",
-                "Falloff Bias:falloffBias:0.2",
-                "Edge Sharpness:edgeSharpness:1",
-                "Blur Radius:blurRadius:6",
-                "Blur Deviation:blurDeviation:3"
-            ]
-            ConfigSlider {
-                label: qsTr(modelData.split(":")[0])
-                config: ambientOcclusion.config
-                property: modelData.split(":")[1]
-                max: modelData.split(":")[2]
-            }
-        }
-        Repeater {
-            model: [
-                "Samples:numSamples:32",
-                "Spiral Turns:numSpiralTurns:30:"
-            ]
+            model: [ "Opaque:DrawOpaqueDeferred", "Transparent:DrawTransparentDeferred",
+                    "Opaque Overlays:DrawOverlay3DOpaque", "Transparent Overlays:DrawOverlay3DTransparent" ]
             ConfigSlider {
                 label: qsTr(modelData.split(":")[0])
                 integral: true
-                config: ambientOcclusion.config
-                property: modelData.split(":")[1]
-                max: modelData.split(":")[2]
+                config: Render.getConfig(modelData.split(":")[1])
+                property: "maxDrawn"
+                max: config.numDrawn
+                min: -1
             }
         }
-    }
 
-    Column {
-        id: debug
-        property var config: Render.getConfig("DebugDeferredBuffer")
-
-        function setDebugMode(mode) {
-            debug.config.enabled = (mode != 0);
-            debug.config.mode = mode;
+        Row {
+            CheckBox {
+                text: qsTr("Display Status")
+                onCheckedChanged: { Render.getConfig("DrawStatus").showDisplay = checked }
+            }
+            CheckBox {
+                text: qsTr("Network/Physics Status")
+                onCheckedChanged: { Render.getConfig("DrawStatus").showNetwork = checked }
+            }
         }
 
-        Label { text: qsTr("Debug Buffer") }
-        ExclusiveGroup { id: bufferGroup }
-        Repeater {
-            model: [
-                "Off", "Diffuse", "Metallic", "Roughness", "Normal", "Depth",
-                "Lighting", "Shadow", "Pyramid Depth", "Ambient Occlusion", "Custom Shader"
-            ]
-           RadioButton {
-                text: qsTr(modelData)
-                exclusiveGroup: bufferGroup
-                checked: index == 0
-                onCheckedChanged: if (checked) debug.setDebugMode(index);
+        ConfigSlider {
+            label: qsTr("Tone Mapping Exposure")
+            config: Render.getConfig("ToneMapping")
+            property: "exposure"
+            min: -10; max: 10
+        }
+
+        Column {
+            id: ambientOcclusion
+            property var config: Render.getConfig("AmbientOcclusion")
+
+            Label { text: qsTr("Ambient Occlusion") }
+            // TODO: Add gpuTimer
+            CheckBox { text: qsTr("Dithering"); checked: ambientOcclusion.config.ditheringEnabled }
+            Repeater {
+                model: [
+                    "Resolution Level:resolutionLevel:4",
+                    "Obscurance Level:obscuranceLevel:1",
+                    "Radius:radius:2",
+                    "Falloff Bias:falloffBias:0.2",
+                    "Edge Sharpness:edgeSharpness:1",
+                    "Blur Radius:blurRadius:6",
+                    "Blur Deviation:blurDeviation:3"
+                ]
+                ConfigSlider {
+                    label: qsTr(modelData.split(":")[0])
+                    config: ambientOcclusion.config
+                    property: modelData.split(":")[1]
+                    max: modelData.split(":")[2]
+                }
+            }
+            Repeater {
+                model: [
+                    "Samples:numSamples:32",
+                    "Spiral Turns:numSpiralTurns:30:"
+                ]
+                ConfigSlider {
+                    label: qsTr(modelData.split(":")[0])
+                    integral: true
+                    config: ambientOcclusion.config
+                    property: modelData.split(":")[1]
+                    max: modelData.split(":")[2]
+                }
+            }
+        }
+
+        Column {
+            id: debug
+            property var config: Render.getConfig("DebugDeferredBuffer")
+
+            function setDebugMode(mode) {
+                debug.config.enabled = (mode != 0);
+                debug.config.mode = mode;
+            }
+
+            Label { text: qsTr("Debug Buffer") }
+            ExclusiveGroup { id: bufferGroup }
+            Repeater {
+                model: [
+                    "Off", "Diffuse", "Metallic", "Roughness", "Normal", "Depth",
+                    "Lighting", "Shadow", "Pyramid Depth", "Ambient Occlusion", "Custom Shader"
+                ]
+               RadioButton {
+                    text: qsTr(modelData)
+                    exclusiveGroup: bufferGroup
+                    checked: index == 0
+                    onCheckedChanged: if (checked && index > 0) debug.setDebugMode(index - 1);
+                }
             }
         }
     }
diff --git a/interface/resources/qml/Browser.qml b/interface/resources/qml/Browser.qml
index 382acc237c..89ab333a0d 100644
--- a/interface/resources/qml/Browser.qml
+++ b/interface/resources/qml/Browser.qml
@@ -14,7 +14,8 @@ Window {
     destroyOnInvisible: true
     width: 800
     height: 600
-
+    property alias webView: webview
+    
     Component.onCompleted: {
         visible = true
         addressBar.text = webview.url
@@ -28,6 +29,7 @@ Window {
     }
 
     Item {
+        id:item
         anchors.fill: parent
         Rectangle {
             anchors.left: parent.left
@@ -125,12 +127,10 @@ Window {
                 console.log("New icon: " + icon)
             }
             
-            profile: WebEngineProfile {
-                id: webviewProfile
-                storageName: "qmlUserBrowser"
-            }
-
+            profile: desktop.browserProfile
+    
         }
+
     } // item
     
     Keys.onPressed: {
diff --git a/interface/resources/qml/ForceLoad.qml b/interface/resources/qml/ForceLoad.qml
new file mode 100644
index 0000000000..55d8b98b1b
--- /dev/null
+++ b/interface/resources/qml/ForceLoad.qml
@@ -0,0 +1,12 @@
+import QtQuick 2.0
+import QtMultimedia 5.5
+
+Item {
+    Audio {
+        id: audio
+        autoLoad: true
+        autoPlay: true
+        loops: Audio.Infinite
+    }
+}
+
diff --git a/interface/resources/qml/Stats.qml b/interface/resources/qml/Stats.qml
index 35738c56b1..d2f78191ea 100644
--- a/interface/resources/qml/Stats.qml
+++ b/interface/resources/qml/Stats.qml
@@ -267,15 +267,9 @@ Item {
                     Text {
                         color: root.fontColor;
                         font.pixelSize: root.fontSize
-                        visible: root.showAcuity
+                        visible: root.expanded
                         text: "LOD: " + root.lodStatus;
                     }
-                    Text {
-                        color: root.fontColor;
-                        font.pixelSize: root.fontSize
-                        visible: root.expanded && !root.showAcuity
-                        text: root.lodStatsRenderText;
-                    }
                 }
             }
         }
diff --git a/interface/resources/qml/controls/WebView.qml b/interface/resources/qml/controls/WebView.qml
index c7ae322cba..18080cd448 100644
--- a/interface/resources/qml/controls/WebView.qml
+++ b/interface/resources/qml/controls/WebView.qml
@@ -11,6 +11,7 @@ WebEngineView {
         root.javaScriptConsoleMessage.connect(function(level, message, lineNumber, sourceID) {
             console.log("Web Window JS message: " + sourceID + " " + lineNumber + " " +  message);
         });
+
     }
 
     // FIXME hack to get the URL with the auth token included.  Remove when we move to Qt 5.6
@@ -36,6 +37,10 @@ WebEngineView {
         }
     }
 
+    onFeaturePermissionRequested: {
+        grantFeaturePermission(securityOrigin, feature, true);
+    }
+
     onLoadingChanged: {
         // Required to support clicking on "hifi://" links
         if (WebEngineView.LoadStartedStatus == loadRequest.status) {
@@ -48,9 +53,12 @@ WebEngineView {
         }
     }
 
-    profile: WebEngineProfile {
-        id: webviewProfile
-        httpUserAgent: "Mozilla/5.0 (HighFidelityInterface)"
-        storageName: "qmlWebEngine"
+    onNewViewRequested:{
+            var component = Qt.createComponent("../Browser.qml");
+            var newWindow = component.createObject(desktop);
+            request.openIn(newWindow.webView)
     }
+
+
+    profile: desktop.browserProfile
 }
diff --git a/interface/resources/qml/hifi/Desktop.qml b/interface/resources/qml/hifi/Desktop.qml
index 5951101194..5227d3cb2e 100644
--- a/interface/resources/qml/hifi/Desktop.qml
+++ b/interface/resources/qml/hifi/Desktop.qml
@@ -9,7 +9,7 @@ Desktop {
     id: desktop
 
     Component.onCompleted: {
-        WebEngine.settings.javascriptCanOpenWindows = false;
+        WebEngine.settings.javascriptCanOpenWindows = true;
         WebEngine.settings.javascriptCanAccessClipboard = false;
         WebEngine.settings.spatialNavigationEnabled = true;
         WebEngine.settings.localContentCanAccessRemoteUrls = true;
@@ -19,6 +19,12 @@ Desktop {
     property alias toolWindow: toolWindow
     ToolWindow { id: toolWindow }
 
+    property var browserProfile: WebEngineProfile {
+        id: webviewProfile
+        httpUserAgent: "Chrome/48.0 (HighFidelityInterface)"
+        storageName: "qmlWebEngine"
+    }
+
     Action {
         text: "Open Browser"
         shortcut: "Ctrl+B"
diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index 792a06e136..7c1fd9279b 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -210,7 +210,7 @@ static const QString INFO_EDIT_ENTITIES_PATH = "html/edit-commands.html";
 
 static const unsigned int THROTTLED_SIM_FRAMERATE = 15;
 static const int THROTTLED_SIM_FRAME_PERIOD_MS = MSECS_PER_SECOND / THROTTLED_SIM_FRAMERATE;
-static const unsigned int CAPPED_SIM_FRAMERATE = 60;
+static const unsigned int CAPPED_SIM_FRAMERATE = 120;
 static const int CAPPED_SIM_FRAME_PERIOD_MS = MSECS_PER_SECOND / CAPPED_SIM_FRAMERATE;
 
 static const uint32_t INVALID_FRAME = UINT32_MAX;
@@ -1615,13 +1615,7 @@ void Application::paintGL() {
         });
     }
 
-    // Some LOD-like controls need to know a smoothly varying "potential" frame rate that doesn't
-    // include time waiting for sync, and which can report a number above target if we've got the headroom.
-    // In my tests, the following is mostly less than 0.5ms, and never more than 3ms. I don't think its worth measuring during runtime.
-    const float paintWaitAndQTTimerAllowance = 0.001f; // seconds
-    // Store both values now for use by next cycle.
     _lastInstantaneousFps = instantaneousFps;
-    _lastUnsynchronizedFps = 1.0f / (((usecTimestampNow() - now) / (float)USECS_PER_SECOND) + paintWaitAndQTTimerAllowance);
     _pendingPaint = false;
 }
 
@@ -1713,6 +1707,7 @@ bool Application::event(QEvent* event) {
 
     if ((int)event->type() == (int)Paint) {
         paintGL();
+        return true;
     }
 
     if (!_keyboardFocusedItem.isInvalidID()) {
@@ -3099,11 +3094,7 @@ void Application::update(float deltaTime) {
     bool showWarnings = Menu::getInstance()->isOptionChecked(MenuOption::PipelineWarnings);
     PerformanceWarning warn(showWarnings, "Application::update()");
 
-    if (DependencyManager::get<LODManager>()->getUseAcuity()) {
-        updateLOD();
-    } else {
-        DependencyManager::get<LODManager>()->updatePIDRenderDistance(getTargetFrameRate(), getLastInstanteousFps(), deltaTime, isThrottleRendering());
-    }
+    updateLOD();
 
     {
         PerformanceTimer perfTimer("devices");
@@ -3607,7 +3598,7 @@ glm::vec3 Application::getSunDirection() {
 // FIXME, preprocessor guard this check to occur only in DEBUG builds
 static QThread * activeRenderingThread = nullptr;
 
-PickRay Application::computePickRay(float x, float y) {
+PickRay Application::computePickRay(float x, float y) const {
     vec2 pickPoint { x, y };
     PickRay result;
     if (isHMDMode()) {
@@ -4729,7 +4720,7 @@ glm::uvec2 Application::getCanvasSize() const {
     return glm::uvec2(_glWidget->width(), _glWidget->height());
 }
 
-QRect Application::getApplicationGeometry() const { 
+QRect Application::getRenderingGeometry() const {
     auto geometry = _glWidget->geometry(); 
     auto topLeft = geometry.topLeft();
     auto topLeftScreen = _glWidget->mapToGlobal(topLeft);
diff --git a/interface/src/Application.h b/interface/src/Application.h
index 482f0afef6..96bafce23f 100644
--- a/interface/src/Application.h
+++ b/interface/src/Application.h
@@ -114,7 +114,7 @@ public:
     bool eventFilter(QObject* object, QEvent* event) override;
 
     glm::uvec2 getCanvasSize() const;
-    QRect getApplicationGeometry() const;
+    QRect getRenderingGeometry() const;
 
     glm::uvec2 getUiSize() const;
     QSize getDeviceSize() const;
@@ -157,7 +157,6 @@ public:
     float getFps() const { return _fps; }
     float getTargetFrameRate(); // frames/second
     float getLastInstanteousFps() const { return _lastInstantaneousFps; }
-    float getLastUnsynchronizedFps() const { return _lastUnsynchronizedFps; }
 
     float getFieldOfView() { return _fieldOfView.get(); }
     void setFieldOfView(float fov);
@@ -169,7 +168,7 @@ public:
 
     virtual ViewFrustum* getCurrentViewFrustum() override { return getDisplayViewFrustum(); }
     virtual QThread* getMainThread() override { return thread(); }
-    virtual PickRay computePickRay(float x, float y) override;
+    virtual PickRay computePickRay(float x, float y) const override;
     virtual glm::vec3 getAvatarPosition() const override;
     virtual qreal getDevicePixelRatio() override;
 
@@ -405,7 +404,6 @@ private:
     QElapsedTimer _timerStart;
     QElapsedTimer _lastTimeUpdated;
     float _lastInstantaneousFps { 0.0f };
-    float _lastUnsynchronizedFps { 0.0f };
 
     ShapeManager _shapeManager;
     PhysicalEntitySimulation _entitySimulation;
diff --git a/interface/src/LODManager.cpp b/interface/src/LODManager.cpp
index 389e43a5ff..64b506059c 100644
--- a/interface/src/LODManager.cpp
+++ b/interface/src/LODManager.cpp
@@ -20,29 +20,8 @@
 
 Setting::Handle<float> desktopLODDecreaseFPS("desktopLODDecreaseFPS", DEFAULT_DESKTOP_LOD_DOWN_FPS);
 Setting::Handle<float> hmdLODDecreaseFPS("hmdLODDecreaseFPS", DEFAULT_HMD_LOD_DOWN_FPS);
-// There are two different systems in use, based on lodPreference:
-// pid: renderDistance is adjusted by a PID such that frame rate targets are met.
-// acuity:  a pseudo-acuity target is held, or adjusted to match minimum frame rates (and a PID controlls avatar rendering distance)
-// If unspecified, acuity is used only if user has specified non-default minumum frame rates.
-Setting::Handle<int> lodPreference("lodPreference", (int)LODManager::LODPreference::acuity);
-const float SMALLEST_REASONABLE_HORIZON = 50.0f; // meters
-Setting::Handle<float> renderDistanceInverseHighLimit("renderDistanceInverseHighLimit", 1.0f / SMALLEST_REASONABLE_HORIZON);
-void LODManager::setRenderDistanceInverseHighLimit(float newValue) {
-    renderDistanceInverseHighLimit.set(newValue); // persist it, and tell all the controllers that use it
-    _renderDistanceController.setControlledValueHighLimit(newValue);
-}
 
 LODManager::LODManager() {
-
-    setRenderDistanceInverseHighLimit(renderDistanceInverseHighLimit.get());
-    setRenderDistanceInverseLowLimit(1.0f / (float)TREE_SCALE);
-    // Advice for tuning parameters:
-    // See PIDController.h. There's a section on tuning in the reference.
-    // Turn on logging with the following (or from js with LODManager.setRenderDistanceControllerHistory("render pid", 240))
-    //setRenderDistanceControllerHistory("render pid", 60 * 4);
-    // Note that extra logging/hysteresis is turned off in Avatar.cpp when the above logging is on.
-    setRenderDistanceKP(0.000012f); // Usually about 0.6 of largest that doesn't oscillate when other parameters 0.
-    setRenderDistanceKI(0.00002f); // Big enough to bring us to target with the above KP.
 }
 
 float LODManager::getLODDecreaseFPS() {
@@ -234,53 +213,7 @@ QString LODManager::getLODFeedbackText() {
     return result;
 }
 
-static float renderDistance = (float)TREE_SCALE;
-static int renderedCount = 0;
-static int lastRenderedCount = 0;
-bool LODManager::getUseAcuity() { return lodPreference.get() == (int)LODManager::LODPreference::acuity; }
-void LODManager::setUseAcuity(bool newValue) { lodPreference.set(newValue ? (int)LODManager::LODPreference::acuity : (int)LODManager::LODPreference::pid); }
-float LODManager::getRenderDistance() {
-    return renderDistance;
-}
-int LODManager::getRenderedCount() {
-    return lastRenderedCount;
-}
-QString LODManager::getLODStatsRenderText() {
-    const QString label = "Rendered objects: ";
-    return label + QString::number(getRenderedCount()) + " w/in " + QString::number((int)getRenderDistance()) + "m";
-}
-// compare autoAdjustLOD()
-void LODManager::updatePIDRenderDistance(float targetFps, float measuredFps, float deltaTime, bool isThrottled) {
-    float distance;
-    if (!isThrottled) {
-        _renderDistanceController.setMeasuredValueSetpoint(targetFps); // No problem updating in flight.
-        // The PID controller raises the controlled value when the measured value goes up.
-        // The measured value is frame rate. When the controlled value (1 / render cutoff distance)
-        // goes up, the render cutoff distance gets closer, the number of rendered avatars is less, and frame rate
-        // goes up.
-        distance = 1.0f / _renderDistanceController.update(measuredFps, deltaTime);
-    } else {
-        // Here we choose to just use the maximum render cutoff distance if throttled.
-        distance = 1.0f / _renderDistanceController.getControlledValueLowLimit();
-    }
-    _renderDistanceAverage.updateAverage(distance);
-    renderDistance = _renderDistanceAverage.getAverage(); // average only once per cycle
-    lastRenderedCount = renderedCount;
-    renderedCount = 0;
-}
-
 bool LODManager::shouldRender(const RenderArgs* args, const AABox& bounds) {
-    // NOTE: this branch of code is the alternate form of LOD that uses PID controllers.
-    if (!getUseAcuity()) {
-        float distanceToCamera = glm::length(bounds.calcCenter() - args->_viewFrustum->getPosition());
-        float largestDimension = bounds.getLargestDimension();
-        const float scenerySize = 300; // meters
-        bool isRendered = (largestDimension > scenerySize) || // render scenery regardless of distance
-            (distanceToCamera < renderDistance + largestDimension);
-        renderedCount += isRendered ? 1 : 0;
-        return isRendered;
-    }
-    
     // FIXME - eventually we want to use the render accuracy as an indicator for the level of detail
     // to use in rendering.
     float renderAccuracy = args->_viewFrustum->calculateRenderAccuracy(bounds, args->_sizeScale, args->_boundaryLevelAdjust);
@@ -299,12 +232,6 @@ void LODManager::setBoundaryLevelAdjust(int boundaryLevelAdjust) {
 void LODManager::loadSettings() {
     setDesktopLODDecreaseFPS(desktopLODDecreaseFPS.get());
     setHMDLODDecreaseFPS(hmdLODDecreaseFPS.get());
-
-    if (lodPreference.get() == (int)LODManager::LODPreference::unspecified) {
-        setUseAcuity((getDesktopLODDecreaseFPS() != DEFAULT_DESKTOP_LOD_DOWN_FPS) || (getHMDLODDecreaseFPS() != DEFAULT_HMD_LOD_DOWN_FPS));
-    }
-    Menu::getInstance()->getActionForOption(MenuOption::LodTools)->setEnabled(getUseAcuity());
-    Menu::getInstance()->getSubMenuFromName(MenuOption::RenderResolution, Menu::getInstance()->getSubMenuFromName("Render", Menu::getInstance()->getMenu("Developer")))->setEnabled(getUseAcuity());
 }
 
 void LODManager::saveSettings() {
diff --git a/interface/src/LODManager.h b/interface/src/LODManager.h
index 4863324161..ef4d9c8e62 100644
--- a/interface/src/LODManager.h
+++ b/interface/src/LODManager.h
@@ -18,8 +18,8 @@
 #include <PIDController.h>
 #include <SimpleMovingAverage.h>
 
-const float DEFAULT_DESKTOP_LOD_DOWN_FPS = 15.0;
-const float DEFAULT_HMD_LOD_DOWN_FPS = 30.0;
+const float DEFAULT_DESKTOP_LOD_DOWN_FPS = 30.0;
+const float DEFAULT_HMD_LOD_DOWN_FPS = 45.0;
 const float MAX_LIKELY_DESKTOP_FPS = 59.0; // this is essentially, V-synch - 1 fps
 const float MAX_LIKELY_HMD_FPS = 74.0; // this is essentially, V-synch - 1 fps
 const float INCREASE_LOD_GAP = 15.0f;
@@ -76,27 +76,6 @@ public:
     Q_INVOKABLE float getLODDecreaseFPS();
     Q_INVOKABLE float getLODIncreaseFPS();
     
-    enum class LODPreference {
-        pid = 0,
-        acuity,
-        unspecified
-    };
-    static bool getUseAcuity();
-    static void setUseAcuity(bool newValue);
-    Q_INVOKABLE void setRenderDistanceKP(float newValue) { _renderDistanceController.setKP(newValue); }
-    Q_INVOKABLE void setRenderDistanceKI(float newValue) { _renderDistanceController.setKI(newValue); }
-    Q_INVOKABLE void setRenderDistanceKD(float newValue) { _renderDistanceController.setKD(newValue); }
-    Q_INVOKABLE bool getRenderDistanceControllerIsLogging() { return _renderDistanceController.getIsLogging(); }
-    Q_INVOKABLE void setRenderDistanceControllerHistory(QString label, int size) { return _renderDistanceController.setHistorySize(label, size); }
-    Q_INVOKABLE float getRenderDistanceInverseLowLimit() { return _renderDistanceController.getControlledValueLowLimit(); }
-    Q_INVOKABLE void setRenderDistanceInverseLowLimit(float newValue) { _renderDistanceController.setControlledValueLowLimit(newValue); }
-    Q_INVOKABLE float getRenderDistanceInverseHighLimit() { return _renderDistanceController.getControlledValueHighLimit(); }
-    Q_INVOKABLE void setRenderDistanceInverseHighLimit(float newValue);
-    void updatePIDRenderDistance(float targetFps, float measuredFps, float deltaTime, bool isThrottled);
-    float getRenderDistance();
-    int getRenderedCount();
-    QString getLODStatsRenderText();
-
     static bool shouldRender(const RenderArgs* args, const AABox& bounds);
     void autoAdjustLOD(float currentFPS);
     
@@ -126,9 +105,6 @@ private:
     SimpleMovingAverage _fpsAverageStartWindow = START_DELAY_SAMPLES_OF_FRAMES;
     SimpleMovingAverage _fpsAverageDownWindow = DOWN_SHIFT_SAMPLES_OF_FRAMES;
     SimpleMovingAverage _fpsAverageUpWindow = UP_SHIFT_SAMPLES_OF_FRAMES;
-    
-    PIDController _renderDistanceController{};
-    SimpleMovingAverage _renderDistanceAverage{ 10 };
 };
 
 #endif // hifi_LODManager_h
diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index 6da4481840..8e48237b8e 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -162,7 +162,7 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
 void AvatarManager::simulateAvatarFades(float deltaTime) {
     QVector<AvatarSharedPointer>::iterator fadingIterator = _avatarFades.begin();
 
-    const float SHRINK_RATE = 0.9f;
+    const float SHRINK_RATE = 0.15f;
     const float MIN_FADE_SCALE = MIN_AVATAR_SCALE;
 
     render::ScenePointer scene = qApp->getMain3DScene();
diff --git a/interface/src/avatar/MyAvatar.h b/interface/src/avatar/MyAvatar.h
index 98d25a64c8..8c84299e08 100644
--- a/interface/src/avatar/MyAvatar.h
+++ b/interface/src/avatar/MyAvatar.h
@@ -421,8 +421,8 @@ private:
     AtRestDetector _hmdAtRestDetector;
     bool _lastIsMoving { false };
     bool _hoverReferenceCameraFacingIsCaptured { false };
-    glm::vec3 _hoverReferenceCameraFacing; // hmd sensor space
-    
+    glm::vec3 _hoverReferenceCameraFacing { 0.0f, 0.0f, -1.0f }; // hmd sensor space
+
     float AVATAR_MOVEMENT_ENERGY_CONSTANT { 0.001f };
     float AUDIO_ENERGY_CONSTANT { 0.000001f };
     float MAX_AVATAR_MOVEMENT_PER_FRAME { 30.0f };
diff --git a/interface/src/avatar/SkeletonModel.cpp b/interface/src/avatar/SkeletonModel.cpp
index c77c4fdd78..e4c98215c2 100644
--- a/interface/src/avatar/SkeletonModel.cpp
+++ b/interface/src/avatar/SkeletonModel.cpp
@@ -144,6 +144,7 @@ void SkeletonModel::updateRig(float deltaTime, glm::mat4 parentTransform) {
         } else {
             handParams.isRightEnabled = false;
         }
+        handParams.bodyCapsuleRadius = myAvatar->getCharacterController()->getCapsuleRadius();
 
         _rig->updateFromHandParameters(handParams, deltaTime);
 
diff --git a/interface/src/ui/ApplicationCompositor.cpp b/interface/src/ui/ApplicationCompositor.cpp
index 76bf48b45e..37eff80df9 100644
--- a/interface/src/ui/ApplicationCompositor.cpp
+++ b/interface/src/ui/ApplicationCompositor.cpp
@@ -335,6 +335,7 @@ void ApplicationCompositor::displayOverlayTextureHmd(RenderArgs* renderArgs, int
 
 QPointF ApplicationCompositor::getMouseEventPosition(QMouseEvent* event) {
     if (qApp->isHMDMode()) {
+        QMutexLocker locker(&_reticlePositionInHMDLock);
         return QPointF(_reticlePositionInHMD.x, _reticlePositionInHMD.y);
     }
     return event->localPos();
@@ -349,7 +350,7 @@ void ApplicationCompositor::handleLeaveEvent() {
 
     if (shouldCaptureMouse()) {
         QWidget* mainWidget = (QWidget*)qApp->getWindow();
-        QRect mainWidgetFrame = qApp->getApplicationGeometry();
+        QRect mainWidgetFrame = qApp->getRenderingGeometry();
         QRect uncoveredRect = mainWidgetFrame;
         foreach(QWidget* widget, QApplication::topLevelWidgets()) {
             if (widget->isWindow() && widget->isVisible() && widget != mainWidget) {
@@ -388,6 +389,7 @@ bool ApplicationCompositor::handleRealMouseMoveEvent(bool sendFakeEvent) {
 
     // If we're in HMD mode
     if (shouldCaptureMouse()) {
+        QMutexLocker locker(&_reticlePositionInHMDLock);
         auto newPosition = QCursor::pos();
         auto changeInRealMouse = newPosition - _lastKnownRealMouse;
         auto newReticlePosition = _reticlePositionInHMD + toGlm(changeInRealMouse);
@@ -403,6 +405,7 @@ bool ApplicationCompositor::handleRealMouseMoveEvent(bool sendFakeEvent) {
 
 glm::vec2 ApplicationCompositor::getReticlePosition() {
     if (qApp->isHMDMode()) {
+        QMutexLocker locker(&_reticlePositionInHMDLock);
         return _reticlePositionInHMD;
     }
     return toGlm(QCursor::pos());
@@ -410,6 +413,7 @@ glm::vec2 ApplicationCompositor::getReticlePosition() {
 
 void ApplicationCompositor::setReticlePosition(glm::vec2 position, bool sendFakeEvent) {
     if (qApp->isHMDMode()) {
+        QMutexLocker locker(&_reticlePositionInHMDLock);
         const float MOUSE_EXTENTS_VERT_ANGULAR_SIZE = 170.0f; // 5deg from poles
         const float MOUSE_EXTENTS_VERT_PIXELS = VIRTUAL_SCREEN_SIZE_Y * (MOUSE_EXTENTS_VERT_ANGULAR_SIZE / DEFAULT_HMD_UI_VERT_ANGULAR_SIZE);
         const float MOUSE_EXTENTS_HORZ_ANGULAR_SIZE = 360.0f; // full sphere
diff --git a/interface/src/ui/ApplicationCompositor.h b/interface/src/ui/ApplicationCompositor.h
index 1fb37c3085..5489bffa02 100644
--- a/interface/src/ui/ApplicationCompositor.h
+++ b/interface/src/ui/ApplicationCompositor.h
@@ -9,11 +9,13 @@
 #ifndef hifi_ApplicationCompositor_h
 #define hifi_ApplicationCompositor_h
 
+#include <atomic>
+#include <cstdint>
+
 #include <QCursor>
 #include <QMouseEvent>
 #include <QObject>
 #include <QPropertyAnimation>
-#include <cstdint>
 
 #include <EntityItemID.h>
 #include <GeometryCache.h>
@@ -81,19 +83,19 @@ public:
     float getAlpha() const { return _alpha; }
     void setAlpha(float alpha) { _alpha = alpha; }
 
-    Q_INVOKABLE bool getReticleVisible() { return _reticleVisible; }
-    Q_INVOKABLE void setReticleVisible(bool visible) { _reticleVisible = visible; }
+    bool getReticleVisible() { return _reticleVisible; }
+    void setReticleVisible(bool visible) { _reticleVisible = visible; }
 
-    Q_INVOKABLE float getReticleDepth() { return _reticleDepth; }
-    Q_INVOKABLE void setReticleDepth(float depth) { _reticleDepth = depth; }
+    float getReticleDepth() { return _reticleDepth; }
+    void setReticleDepth(float depth) { _reticleDepth = depth; }
 
-    Q_INVOKABLE glm::vec2 getReticlePosition();
-    Q_INVOKABLE void setReticlePosition(glm::vec2 position, bool sendFakeEvent = true);
+    glm::vec2 getReticlePosition();
+    void setReticlePosition(glm::vec2 position, bool sendFakeEvent = true);
 
-    Q_INVOKABLE void setReticleApparentPosition(glm::vec3 position) { _drawAt3D = true; _drawAt3DPosition = position; }
-    Q_INVOKABLE void restoreReticleApparentPosition() { _drawAt3D = false; }
+    void setReticleApparentPosition(glm::vec3 position) { _drawAt3D = true; _drawAt3DPosition = position; }
+    void restoreReticleApparentPosition() { _drawAt3D = false; }
 
-    Q_INVOKABLE glm::vec2 getReticleMaximumPosition() const;
+    glm::vec2 getReticleMaximumPosition() const;
 
     ReticleInterface* getReticleInterface() { return _reticleInterface; }
 
@@ -141,21 +143,22 @@ private:
 
     std::unique_ptr<QPropertyAnimation> _alphaPropertyAnimation;
 
-    bool _reticleVisible { true };
-    float _reticleDepth { 1.0f };
-    bool _drawAt3D { false };
-    glm::vec3 _drawAt3DPosition;
+    std::atomic<bool> _reticleVisible { true };
+    std::atomic<float> _reticleDepth { 1.0f };
 
     // NOTE: when the compositor is running in HMD mode, it will control the reticle position as a custom
     // application specific position, when it's in desktop mode, the reticle position will simply move
     // the system mouse.
-    glm::vec2 _reticlePositionInHMD{ 0.0f, 0.0f };
+    glm::vec2 _reticlePositionInHMD { 0.0f, 0.0f };
+    mutable QMutex _reticlePositionInHMDLock { QMutex::Recursive };
+
+    bool _drawAt3D { false };
+    glm::vec3 _drawAt3DPosition;
+
     QPointF _lastKnownRealMouse;
-    QPoint _lastKnownCursorPos;
     bool _ignoreMouseMove { false };
 
     ReticleInterface* _reticleInterface;
-
 };
 
 // Scripting interface available to control the Reticle
diff --git a/interface/src/ui/ApplicationOverlay.cpp b/interface/src/ui/ApplicationOverlay.cpp
index b654f797ec..67b5135e0c 100644
--- a/interface/src/ui/ApplicationOverlay.cpp
+++ b/interface/src/ui/ApplicationOverlay.cpp
@@ -252,12 +252,8 @@ void ApplicationOverlay::buildFramebufferObject() {
     PROFILE_RANGE(__FUNCTION__);
 
     auto uiSize = qApp->getUiSize();
-    QSize desiredSize (uiSize.x, uiSize.y);
-    int currentWidth = _overlayFramebuffer ? _overlayFramebuffer->getWidth() : 0;
-    int currentHeight = _overlayFramebuffer ? _overlayFramebuffer->getHeight() : 0;
-    QSize frameBufferCurrentSize(currentWidth, currentHeight);
 
-    if (_overlayFramebuffer && desiredSize == frameBufferCurrentSize) {
+    if (_overlayFramebuffer && uiSize == _overlayFramebuffer->getSize()) {
         // Already built
         return;
     }
@@ -271,8 +267,8 @@ void ApplicationOverlay::buildFramebufferObject() {
     _overlayFramebuffer = gpu::FramebufferPointer(gpu::Framebuffer::create());
 
    auto colorFormat = gpu::Element(gpu::VEC4, gpu::NUINT8, gpu::RGBA);
-   auto width = desiredSize.width();
-   auto height = desiredSize.height();
+   auto width = uiSize.x;
+   auto height = uiSize.y;
 
    auto defaultSampler = gpu::Sampler(gpu::Sampler::FILTER_MIN_MAG_LINEAR);
    _overlayColorTexture = gpu::TexturePointer(gpu::Texture::create2D(colorFormat, width, height, defaultSampler));
diff --git a/interface/src/ui/PreferencesDialog.cpp b/interface/src/ui/PreferencesDialog.cpp
index 80f2989127..93bacdd402 100644
--- a/interface/src/ui/PreferencesDialog.cpp
+++ b/interface/src/ui/PreferencesDialog.cpp
@@ -87,13 +87,6 @@ void setupPreferences() {
     }
     
     static const QString LOD_TUNING("Level of Detail Tuning");
-    CheckPreference* acuityToggle;
-    {
-        auto getter = []()->bool { return DependencyManager::get<LODManager>()->getUseAcuity(); };
-        auto setter = [](bool value) { DependencyManager::get<LODManager>()->setUseAcuity(value); };
-        preferences->addPreference(acuityToggle = new CheckPreference(LOD_TUNING, "Render based on visual acuity", getter, setter));
-    }
-
     {
         auto getter = []()->float { return DependencyManager::get<LODManager>()->getDesktopLODDecreaseFPS(); };
         auto setter = [](float value) { DependencyManager::get<LODManager>()->setDesktopLODDecreaseFPS(value); };
@@ -101,7 +94,6 @@ void setupPreferences() {
         preference->setMin(0);
         preference->setMax(120);
         preference->setStep(1);
-        preference->setEnabler(acuityToggle);
         preferences->addPreference(preference);
     }
 
@@ -112,18 +104,6 @@ void setupPreferences() {
         preference->setMin(0);
         preference->setMax(120);
         preference->setStep(1);
-        preference->setEnabler(acuityToggle);
-        preferences->addPreference(preference);
-    }
-
-    {
-        auto getter = []()->float { return 1.0f / DependencyManager::get<LODManager>()->getRenderDistanceInverseHighLimit(); };
-        auto setter = [](float value) { DependencyManager::get<LODManager>()->setRenderDistanceInverseHighLimit(1.0f / value); };
-        auto preference = new SpinnerPreference(LOD_TUNING, "Minimum Display Distance", getter, setter);
-        preference->setMin(5);
-        preference->setMax(32768);
-        preference->setStep(1);
-        preference->setEnabler(acuityToggle, true);
         preferences->addPreference(preference);
     }
 
@@ -274,7 +254,7 @@ void setupPreferences() {
     {
         auto getter = []()->float { return DependencyManager::get<AudioClient>()->getOutputBufferSize(); };
         auto setter = [](float value) { DependencyManager::get<AudioClient>()->setOutputBufferSize(value); };
-        auto preference = new SpinnerPreference(AUDIO, "Output Buffer Size (frames)", getter, setter);
+        auto preference = new SpinnerPreference(AUDIO, "Output Buffer Initial Size (frames)", getter, setter);
         preference->setMin(1);
         preference->setMax(20);
         preference->setStep(1);
diff --git a/interface/src/ui/Stats.cpp b/interface/src/ui/Stats.cpp
index 1ee26a865d..c9c4c68dc9 100644
--- a/interface/src/ui/Stats.cpp
+++ b/interface/src/ui/Stats.cpp
@@ -283,9 +283,7 @@ void Stats::updateStats(bool force) {
         STAT_UPDATE(localLeaves, (int)OctreeElement::getLeafNodeCount());
         // LOD Details
         STAT_UPDATE(lodStatus, "You can see " + DependencyManager::get<LODManager>()->getLODFeedbackText());
-        STAT_UPDATE(lodStatsRenderText, DependencyManager::get<LODManager>()->getLODStatsRenderText());
     }
-    STAT_UPDATE(showAcuity, (_expanded || force) && DependencyManager::get<LODManager>()->getUseAcuity());
 
     bool performanceTimerIsActive = PerformanceTimer::isActive();
     bool displayPerf = _expanded && Menu::getInstance()->isOptionChecked(MenuOption::DisplayDebugTimingDetails);
diff --git a/interface/src/ui/Stats.h b/interface/src/ui/Stats.h
index bebfbf6f70..ba3c8f2391 100644
--- a/interface/src/ui/Stats.h
+++ b/interface/src/ui/Stats.h
@@ -30,7 +30,6 @@ class Stats : public QQuickItem {
     Q_PROPERTY(QString monospaceFont READ monospaceFont CONSTANT)
     Q_PROPERTY(float audioPacketlossUpstream READ getAudioPacketLossUpstream)
     Q_PROPERTY(float audioPacketlossDownstream READ getAudioPacketLossDownstream)
-    Q_PROPERTY(bool showAcuity READ getShowAcuity WRITE setShowAcuity NOTIFY showAcuityChanged)
 
     STATS_PROPERTY(int, serverCount, 0)
     STATS_PROPERTY(int, renderrate, 0)
@@ -80,7 +79,6 @@ class Stats : public QQuickItem {
     STATS_PROPERTY(QString, packetStats, QString())
     STATS_PROPERTY(QString, lodStatus, QString())
     STATS_PROPERTY(QString, timingStats, QString())
-    STATS_PROPERTY(QString, lodStatsRenderText, QString())
     STATS_PROPERTY(int, serverElements, 0)
     STATS_PROPERTY(int, serverInternal, 0)
     STATS_PROPERTY(int, serverLeaves, 0)
@@ -112,15 +110,12 @@ public:
             emit expandedChanged();
         }
     }
-    bool getShowAcuity() { return _showAcuity; }
-    void setShowAcuity(bool newValue) { _showAcuity = newValue; }
 
 public slots:
     void forceUpdateStats() { updateStats(true); }
 
 signals:
     void expandedChanged();
-    void showAcuityChanged();
     void timingExpandedChanged();
     void serverCountChanged();
     void renderrateChanged();
@@ -128,7 +123,6 @@ signals:
     void simrateChanged();
     void avatarSimrateChanged();
     void avatarCountChanged();
-    void lodStatsRenderTextChanged();
     void packetInCountChanged();
     void packetOutCountChanged();
     void mbpsInChanged();
@@ -182,7 +176,6 @@ private:
     int _recentMaxPackets{ 0 } ; // recent max incoming voxel packets to process
     bool _resetRecentMaxPacketsSoon{ true };
     bool _expanded{ false };
-    bool _showAcuity{ false };
     bool _timingExpanded{ false };
     QString _monospaceFont;
     const AudioIOStats* _audioStats;
diff --git a/libraries/animation/src/AnimInverseKinematics.cpp b/libraries/animation/src/AnimInverseKinematics.cpp
index ff1dea3d48..48ad9b852d 100644
--- a/libraries/animation/src/AnimInverseKinematics.cpp
+++ b/libraries/animation/src/AnimInverseKinematics.cpp
@@ -670,7 +670,7 @@ void AnimInverseKinematics::initConstraints() {
             stConstraint->setTwistLimits(-MAX_SHOULDER_TWIST, MAX_SHOULDER_TWIST);
 
             std::vector<float> minDots;
-            const float MAX_SHOULDER_SWING = PI / 20.0f;
+            const float MAX_SHOULDER_SWING = PI / 6.0f;
             minDots.push_back(cosf(MAX_SHOULDER_SWING));
             stConstraint->setSwingLimits(minDots);
 
diff --git a/libraries/animation/src/Rig.cpp b/libraries/animation/src/Rig.cpp
index 817054a9f5..3952dc5b40 100644
--- a/libraries/animation/src/Rig.cpp
+++ b/libraries/animation/src/Rig.cpp
@@ -1080,8 +1080,31 @@ void Rig::updateEyeJoint(int index, const glm::vec3& modelTranslation, const glm
 
 void Rig::updateFromHandParameters(const HandParameters& params, float dt) {
     if (_animSkeleton && _animNode) {
+
+        const float HAND_RADIUS = 0.05f;
+        const float BODY_RADIUS = params.bodyCapsuleRadius;
+        const float MIN_LENGTH = 1.0e-4f;
+
+        // project the hips onto the xz plane.
+        auto hipsTrans = _internalPoseSet._absolutePoses[_animSkeleton->nameToJointIndex("Hips")].trans;
+        const glm::vec2 bodyCircleCenter(hipsTrans.x, hipsTrans.z);
+
         if (params.isLeftEnabled) {
-            _animVars.set("leftHandPosition", params.leftPosition);
+
+            // project the hand position onto the xz plane.
+            glm::vec2 handCircleCenter(params.leftPosition.x, params.leftPosition.z);
+
+            // check for 2d overlap of the hand and body circles.
+            auto circleToCircle = handCircleCenter - bodyCircleCenter;
+            const float circleToCircleLength = glm::length(circleToCircle);
+            const float penetrationDistance = HAND_RADIUS + BODY_RADIUS - circleToCircleLength;
+            if (penetrationDistance > 0.0f && circleToCircleLength > MIN_LENGTH) {
+                // push the hands out of the body
+                handCircleCenter += penetrationDistance * glm::normalize(circleToCircle);
+            }
+
+            glm::vec3 handPosition(handCircleCenter.x, params.leftPosition.y, handCircleCenter.y);
+            _animVars.set("leftHandPosition", handPosition);
             _animVars.set("leftHandRotation", params.leftOrientation);
             _animVars.set("leftHandType", (int)IKTarget::Type::RotationAndPosition);
         } else {
@@ -1089,8 +1112,23 @@ void Rig::updateFromHandParameters(const HandParameters& params, float dt) {
             _animVars.unset("leftHandRotation");
             _animVars.set("leftHandType", (int)IKTarget::Type::HipsRelativeRotationAndPosition);
         }
+
         if (params.isRightEnabled) {
-            _animVars.set("rightHandPosition", params.rightPosition);
+
+            // project the hand position onto the xz plane.
+            glm::vec2 handCircleCenter(params.rightPosition.x, params.rightPosition.z);
+
+            // check for 2d overlap of the hand and body circles.
+            auto circleToCircle = handCircleCenter - bodyCircleCenter;
+            const float circleToCircleLength = glm::length(circleToCircle);
+            const float penetrationDistance = HAND_RADIUS + BODY_RADIUS - circleToCircleLength;
+            if (penetrationDistance > 0.0f && circleToCircleLength > MIN_LENGTH) {
+                // push the hands out of the body
+                handCircleCenter += penetrationDistance * glm::normalize(circleToCircle);
+            }
+
+            glm::vec3 handPosition(handCircleCenter.x, params.rightPosition.y, handCircleCenter.y);
+            _animVars.set("rightHandPosition", handPosition);
             _animVars.set("rightHandRotation", params.rightOrientation);
             _animVars.set("rightHandType", (int)IKTarget::Type::RotationAndPosition);
         } else {
diff --git a/libraries/animation/src/Rig.h b/libraries/animation/src/Rig.h
index e4668d6c2a..9c5b014d55 100644
--- a/libraries/animation/src/Rig.h
+++ b/libraries/animation/src/Rig.h
@@ -67,6 +67,7 @@ public:
     struct HandParameters {
         bool isLeftEnabled;
         bool isRightEnabled;
+        float bodyCapsuleRadius;
         glm::vec3 leftPosition = glm::vec3();     // rig space
         glm::quat leftOrientation = glm::quat();  // rig space (z forward)
         glm::vec3 rightPosition = glm::vec3();    // rig space
diff --git a/libraries/audio-client/src/AudioClient.cpp b/libraries/audio-client/src/AudioClient.cpp
index 60c9287912..01ceb73941 100644
--- a/libraries/audio-client/src/AudioClient.cpp
+++ b/libraries/audio-client/src/AudioClient.cpp
@@ -80,8 +80,9 @@ AudioClient::AudioClient() :
     _isStereoInput(false),
     _outputStarveDetectionStartTimeMsec(0),
     _outputStarveDetectionCount(0),
-    _outputBufferSizeFrames("audioOutputBufferSize", DEFAULT_AUDIO_OUTPUT_BUFFER_SIZE_FRAMES),
-    _outputStarveDetectionEnabled("audioOutputStarveDetectionEnabled",
+    _outputBufferSizeFrames("audioOutputBufferSizeFrames", DEFAULT_AUDIO_OUTPUT_BUFFER_SIZE_FRAMES),
+    _sessionOutputBufferSizeFrames(_outputBufferSizeFrames.get()),
+    _outputStarveDetectionEnabled("audioOutputBufferStarveDetectionEnabled",
                                   DEFAULT_AUDIO_OUTPUT_STARVE_DETECTION_ENABLED),
     _outputStarveDetectionPeriodMsec("audioOutputStarveDetectionPeriod",
                                      DEFAULT_AUDIO_OUTPUT_STARVE_DETECTION_PERIOD),
@@ -109,6 +110,7 @@ AudioClient::AudioClient() :
 
     connect(&_receivedAudioStream, &MixedProcessedAudioStream::processSamples,
             this, &AudioClient::processReceivedSamples, Qt::DirectConnection);
+    connect(this, &AudioClient::changeDevice, this, [=](const QAudioDeviceInfo& outputDeviceInfo) { switchOutputToAudioDevice(outputDeviceInfo); });
 
     _inputDevices = getDeviceNames(QAudio::AudioInput);
     _outputDevices = getDeviceNames(QAudio::AudioOutput);
@@ -277,9 +279,9 @@ QAudioDeviceInfo defaultAudioDeviceForMode(QAudio::Mode mode) {
 bool adjustedFormatForAudioDevice(const QAudioDeviceInfo& audioDevice,
                                   const QAudioFormat& desiredAudioFormat,
                                   QAudioFormat& adjustedAudioFormat) {
-    // FIXME: directly using 24khz has a bug somewhere that causes channels to be swapped.
-    // Continue using our internal resampler, for now.
-    if (true || !audioDevice.isFormatSupported(desiredAudioFormat)) {
+    // There had been a note here that 2khz was swapping channels. That doesn't seem to be happening
+    // any more for me. If it does, then we'll want to always resample.
+    if (!audioDevice.isFormatSupported(desiredAudioFormat)) {
         qCDebug(audioclient) << "The desired format for audio I/O is" << desiredAudioFormat;
         qCDebug(audioclient, "The desired audio format is not supported by this device");
 
@@ -287,7 +289,7 @@ bool adjustedFormatForAudioDevice(const QAudioDeviceInfo& audioDevice,
             adjustedAudioFormat = desiredAudioFormat;
             adjustedAudioFormat.setChannelCount(2);
 
-            if (false && audioDevice.isFormatSupported(adjustedAudioFormat)) {
+            if (audioDevice.isFormatSupported(adjustedAudioFormat)) {
                 return true;
             } else {
                 adjustedAudioFormat.setChannelCount(1);
@@ -971,10 +973,8 @@ void AudioClient::outputNotify() {
                     _outputStarveDetectionStartTimeMsec = now;
                     _outputStarveDetectionCount = 0;
 
-                    int oldOutputBufferSizeFrames = _outputBufferSizeFrames.get();
-                    int newOutputBufferSizeFrames = oldOutputBufferSizeFrames + 1;
-                    setOutputBufferSize(newOutputBufferSizeFrames);
-                    newOutputBufferSizeFrames = _outputBufferSizeFrames.get();
+                    int oldOutputBufferSizeFrames = _sessionOutputBufferSizeFrames;
+                    int newOutputBufferSizeFrames = setOutputBufferSize(oldOutputBufferSizeFrames + 1, false);
                     if (newOutputBufferSizeFrames > oldOutputBufferSizeFrames) {
                         qCDebug(audioclient) << "Starve detection threshold met, increasing buffer size to " << newOutputBufferSizeFrames;
                     }
@@ -1038,15 +1038,19 @@ bool AudioClient::switchOutputToAudioDevice(const QAudioDeviceInfo& outputDevice
 
             // setup our general output device for audio-mixer audio
             _audioOutput = new QAudioOutput(outputDeviceInfo, _outputFormat, this);
-            _audioOutput->setBufferSize(_outputBufferSizeFrames.get() * _outputFrameSize * sizeof(int16_t));
+            int osDefaultBufferSize = _audioOutput->bufferSize();
+            int requestedSize = _sessionOutputBufferSizeFrames *_outputFrameSize * sizeof(int16_t);
+            _audioOutput->setBufferSize(requestedSize);
 
             connect(_audioOutput, &QAudioOutput::notify, this, &AudioClient::outputNotify);
 
-            qCDebug(audioclient) << "Output Buffer capacity in frames: " << _audioOutput->bufferSize() / sizeof(int16_t) / (float)_outputFrameSize;
-
             _audioOutputIODevice.start();
             _audioOutput->start(&_audioOutputIODevice);
 
+            qCDebug(audioclient) << "Output Buffer capacity in frames: " << _audioOutput->bufferSize() / sizeof(int16_t) / (float)_outputFrameSize <<
+                "requested bytes:" << requestedSize << "actual bytes:" << _audioOutput->bufferSize() <<
+                "os default:" << osDefaultBufferSize << "period size:" << _audioOutput->periodSize();
+
             // setup a loopback audio output device
             _loopbackAudioOutput = new QAudioOutput(outputDeviceInfo, _outputFormat, this);
 
@@ -1060,19 +1064,23 @@ bool AudioClient::switchOutputToAudioDevice(const QAudioDeviceInfo& outputDevice
     return supportedFormat;
 }
 
-void AudioClient::setOutputBufferSize(int numFrames) {
+int AudioClient::setOutputBufferSize(int numFrames, bool persist) {
     numFrames = std::min(std::max(numFrames, MIN_AUDIO_OUTPUT_BUFFER_SIZE_FRAMES), MAX_AUDIO_OUTPUT_BUFFER_SIZE_FRAMES);
-    if (numFrames != _outputBufferSizeFrames.get()) {
+    if (numFrames != _sessionOutputBufferSizeFrames) {
         qCDebug(audioclient) << "Audio output buffer size (frames): " << numFrames;
-        _outputBufferSizeFrames.set(numFrames);
+        _sessionOutputBufferSizeFrames = numFrames;
+        if (persist) {
+            _outputBufferSizeFrames.set(numFrames);
+        }
 
         if (_audioOutput) {
             // The buffer size can't be adjusted after QAudioOutput::start() has been called, so
             // recreate the device by switching to the default.
             QAudioDeviceInfo outputDeviceInfo = defaultAudioDeviceForMode(QAudio::AudioOutput);
-            switchOutputToAudioDevice(outputDeviceInfo);
+            emit changeDevice(outputDeviceInfo);  // On correct thread, please, as setOutputBufferSize can be called from main thread.
         }
     }
+    return numFrames;
 }
 
 // The following constant is operating system dependent due to differences in
@@ -1143,6 +1151,9 @@ qint64 AudioClient::AudioOutputIODevice::readData(char * data, qint64 maxSize) {
     }
 
     int bytesAudioOutputUnplayed = _audio->_audioOutput->bufferSize() - _audio->_audioOutput->bytesFree();
+    if (!bytesAudioOutputUnplayed) {
+        qCDebug(audioclient) << "empty audio buffer";
+    }
     if (bytesAudioOutputUnplayed == 0 && bytesWritten == 0) {
         _unfulfilledReads++;
     }
diff --git a/libraries/audio-client/src/AudioClient.h b/libraries/audio-client/src/AudioClient.h
index 6b2f39c47c..d3145629ee 100644
--- a/libraries/audio-client/src/AudioClient.h
+++ b/libraries/audio-client/src/AudioClient.h
@@ -57,11 +57,7 @@ static const int NUM_AUDIO_CHANNELS = 2;
 static const int DEFAULT_AUDIO_OUTPUT_BUFFER_SIZE_FRAMES = 3;
 static const int MIN_AUDIO_OUTPUT_BUFFER_SIZE_FRAMES = 1;
 static const int MAX_AUDIO_OUTPUT_BUFFER_SIZE_FRAMES = 20;
-#if defined(Q_OS_ANDROID) || defined(Q_OS_WIN)
-    static const int DEFAULT_AUDIO_OUTPUT_STARVE_DETECTION_ENABLED = false;
-#else
-    static const int DEFAULT_AUDIO_OUTPUT_STARVE_DETECTION_ENABLED = true;
-#endif
+static const int DEFAULT_AUDIO_OUTPUT_STARVE_DETECTION_ENABLED = true;
 static const int DEFAULT_AUDIO_OUTPUT_STARVE_DETECTION_THRESHOLD = 3;
 static const quint64 DEFAULT_AUDIO_OUTPUT_STARVE_DETECTION_PERIOD = 10 * 1000; // 10 Seconds
 
@@ -156,7 +152,7 @@ public slots:
     void processReceivedSamples(const QByteArray& inputBuffer, QByteArray& outputBuffer);
     void sendMuteEnvironmentPacket();
 
-    void setOutputBufferSize(int numFrames);
+    int setOutputBufferSize(int numFrames, bool persist = true);
 
     virtual bool outputLocalInjector(bool isStereo, AudioInjector* injector);
 
@@ -184,6 +180,7 @@ signals:
     void outputBytesToNetwork(int numBytes);
     void inputBytesFromNetwork(int numBytes);
 
+    void changeDevice(const QAudioDeviceInfo& outputDeviceInfo);
     void deviceChanged();
 
     void receivedFirstPacket();
@@ -230,6 +227,7 @@ private:
     int _outputStarveDetectionCount;
 
     Setting::Handle<int> _outputBufferSizeFrames;
+    int _sessionOutputBufferSizeFrames;
     Setting::Handle<bool> _outputStarveDetectionEnabled;
     Setting::Handle<int> _outputStarveDetectionPeriodMsec;
      // Maximum number of starves per _outputStarveDetectionPeriod before increasing buffer size
diff --git a/libraries/entities-renderer/src/RenderableWebEntityItem.cpp b/libraries/entities-renderer/src/RenderableWebEntityItem.cpp
index 8140dd3312..ce3faeb196 100644
--- a/libraries/entities-renderer/src/RenderableWebEntityItem.cpp
+++ b/libraries/entities-renderer/src/RenderableWebEntityItem.cpp
@@ -28,6 +28,11 @@
 
 const float DPI = 30.47f;
 const float METERS_TO_INCHES = 39.3701f;
+static uint32_t _currentWebCount { 0 };
+// Don't allow more than 100 concurrent web views
+static const uint32_t MAX_CONCURRENT_WEB_VIEWS = 100;
+// If a web-view hasn't been rendered for 30 seconds, de-allocate the framebuffer
+static uint64_t MAX_NO_RENDER_INTERVAL = 30 * USECS_PER_SECOND;
 
 EntityItemPointer RenderableWebEntityItem::factory(const EntityItemID& entityID, const EntityItemProperties& properties) {
     EntityItemPointer entity{ new RenderableWebEntityItem(entityID) };
@@ -41,28 +46,123 @@ RenderableWebEntityItem::RenderableWebEntityItem(const EntityItemID& entityItemI
 }
 
 RenderableWebEntityItem::~RenderableWebEntityItem() {
-    if (_webSurface) {
-        _webSurface->pause();
-        _webSurface->disconnect(_connection);
-        // The lifetime of the QML surface MUST be managed by the main thread
-        // Additionally, we MUST use local variables copied by value, rather than
-        // member variables, since they would implicitly refer to a this that 
-        // is no longer valid
-        auto webSurface = _webSurface;
-        AbstractViewStateInterface::instance()->postLambdaEvent([webSurface] {
-            webSurface->deleteLater();
-        });
-    }
-
-    QObject::disconnect(_mousePressConnection);
-    QObject::disconnect(_mouseReleaseConnection);
-    QObject::disconnect(_mouseMoveConnection);
-    QObject::disconnect(_hoverLeaveConnection);
+    destroyWebSurface();
     qDebug() << "Destroyed web entity " << getID();
 }
 
+bool RenderableWebEntityItem::buildWebSurface(EntityTreeRenderer* renderer) {
+    if (_currentWebCount >= MAX_CONCURRENT_WEB_VIEWS) {
+        qWarning() << "Too many concurrent web views to create new view";
+        return false;
+    }
+
+    qDebug() << "Building web surface";
+    ++_currentWebCount;
+    // Save the original GL context, because creating a QML surface will create a new context
+    QOpenGLContext * currentContext = QOpenGLContext::currentContext();
+    QSurface * currentSurface = currentContext->surface();
+    _webSurface = new OffscreenQmlSurface();
+    _webSurface->create(currentContext);
+    _webSurface->setBaseUrl(QUrl::fromLocalFile(PathUtils::resourcesPath() + "/qml/"));
+    _webSurface->load("WebEntity.qml");
+    _webSurface->resume();
+    _webSurface->getRootItem()->setProperty("url", _sourceUrl);
+    _connection = QObject::connect(_webSurface, &OffscreenQmlSurface::textureUpdated, [&](GLuint textureId) {
+        _texture = textureId;
+    });
+    // Restore the original GL context
+    currentContext->makeCurrent(currentSurface);
+
+    auto forwardMouseEvent = [=](const RayToEntityIntersectionResult& intersection, const QMouseEvent* event) {
+        // Ignore mouse interaction if we're locked
+        if (this->getLocked()) {
+            return;
+        }
+
+        if (event->button() == Qt::MouseButton::RightButton) {
+            if (event->type() == QEvent::MouseButtonPress) {
+                const QMouseEvent* mouseEvent = static_cast<const QMouseEvent*>(event);
+                _lastPress = toGlm(mouseEvent->pos());
+            }
+        }
+
+        if (intersection.entityID == getID()) {
+            if (event->button() == Qt::MouseButton::RightButton) {
+                if (event->type() == QEvent::MouseButtonRelease) {
+                    const QMouseEvent* mouseEvent = static_cast<const QMouseEvent*>(event);
+                    ivec2 dist = glm::abs(toGlm(mouseEvent->pos()) - _lastPress);
+                    if (!glm::any(glm::greaterThan(dist, ivec2(1)))) {
+                        AbstractViewStateInterface::instance()->postLambdaEvent([this] {
+                            QMetaObject::invokeMethod(_webSurface->getRootItem(), "goBack");
+                        });
+                    }
+                    _lastPress = ivec2(INT_MIN);
+                }
+                return;
+            }
+
+            // FIXME doesn't work... double click events not received
+            if (event->type() == QEvent::MouseButtonDblClick) {
+                AbstractViewStateInterface::instance()->postLambdaEvent([this] {
+                    _webSurface->getRootItem()->setProperty("url", _sourceUrl);
+                });
+            }
+
+            if (event->button() == Qt::MouseButton::MiddleButton) {
+                if (event->type() == QEvent::MouseButtonRelease) {
+                    AbstractViewStateInterface::instance()->postLambdaEvent([this] {
+                        _webSurface->getRootItem()->setProperty("url", _sourceUrl);
+                    });
+                }
+                return;
+            }
+
+            // Map the intersection point to an actual offscreen pixel
+            glm::vec3 point = intersection.intersection;
+            point -= getPosition();
+            point = glm::inverse(getRotation()) * point;
+            point /= getDimensions();
+            point += 0.5f;
+            point.y = 1.0f - point.y;
+            point *= getDimensions() * METERS_TO_INCHES * DPI;
+
+            if (event->button() == Qt::MouseButton::LeftButton) {
+                if (event->type() == QEvent::MouseButtonPress) {
+                    this->_pressed = true;
+                    this->_lastMove = ivec2((int)point.x, (int)point.y);
+                } else if (event->type() == QEvent::MouseButtonRelease) {
+                    this->_pressed = false;
+                }
+            }
+            if (event->type() == QEvent::MouseMove) {
+                this->_lastMove = ivec2((int)point.x, (int)point.y);
+            }
+
+            // Forward the mouse event.  
+            QMouseEvent mappedEvent(event->type(),
+                QPoint((int)point.x, (int)point.y),
+                event->screenPos(), event->button(),
+                event->buttons(), event->modifiers());
+            QCoreApplication::sendEvent(_webSurface->getWindow(), &mappedEvent);
+        }
+    };
+    _mousePressConnection = QObject::connect(renderer, &EntityTreeRenderer::mousePressOnEntity, forwardMouseEvent);
+    _mouseReleaseConnection = QObject::connect(renderer, &EntityTreeRenderer::mouseReleaseOnEntity, forwardMouseEvent);
+    _mouseMoveConnection = QObject::connect(renderer, &EntityTreeRenderer::mouseMoveOnEntity, forwardMouseEvent);
+    _hoverLeaveConnection = QObject::connect(renderer, &EntityTreeRenderer::hoverLeaveEntity, [=](const EntityItemID& entityItemID, const MouseEvent& event) {
+        if (this->_pressed && this->getID() == entityItemID) {
+            // If the user mouses off the entity while the button is down, simulate a mouse release
+            QMouseEvent mappedEvent(QEvent::MouseButtonRelease,
+                QPoint(_lastMove.x, _lastMove.y),
+                Qt::MouseButton::LeftButton,
+                Qt::MouseButtons(), Qt::KeyboardModifiers());
+            QCoreApplication::sendEvent(_webSurface->getWindow(), &mappedEvent);
+        }
+    });
+    return true;
+}
+
 void RenderableWebEntityItem::render(RenderArgs* args) {
-    
     #ifdef WANT_EXTRA_DEBUGGING
     {
         gpu::Batch& batch = *args->_batch;
@@ -72,116 +172,19 @@ void RenderableWebEntityItem::render(RenderArgs* args) {
     }
     #endif
 
-    QOpenGLContext * currentContext = QOpenGLContext::currentContext();
-    QSurface * currentSurface = currentContext->surface();
     if (!_webSurface) {
-        _webSurface = new OffscreenQmlSurface();
-        _webSurface->create(currentContext);
-        _webSurface->setBaseUrl(QUrl::fromLocalFile(PathUtils::resourcesPath() + "/qml/"));
-        _webSurface->load("WebEntity.qml");
-        _webSurface->resume();
-        _webSurface->getRootItem()->setProperty("url", _sourceUrl);
-        _connection = QObject::connect(_webSurface, &OffscreenQmlSurface::textureUpdated, [&](GLuint textureId) {
-            _texture = textureId;
-        });
-
-        auto forwardMouseEvent = [=](const RayToEntityIntersectionResult& intersection, const QMouseEvent* event) {
-            // Ignore mouse interaction if we're locked
-            if (this->getLocked()) {
-                return;
-            }
-
-            if (event->button() == Qt::MouseButton::RightButton) {
-                if (event->type() == QEvent::MouseButtonPress) {
-                    const QMouseEvent* mouseEvent = static_cast<const QMouseEvent*>(event);
-                    _lastPress = toGlm(mouseEvent->pos());
-                }
-            }
-
-            if (intersection.entityID == getID()) {
-                if (event->button() == Qt::MouseButton::RightButton) {
-                    if (event->type() == QEvent::MouseButtonRelease) {
-                        const QMouseEvent* mouseEvent = static_cast<const QMouseEvent*>(event);
-                        ivec2 dist = glm::abs(toGlm(mouseEvent->pos()) - _lastPress);
-                        if (!glm::any(glm::greaterThan(dist, ivec2(1)))) {
-                            AbstractViewStateInterface::instance()->postLambdaEvent([this] {
-                                QMetaObject::invokeMethod(_webSurface->getRootItem(), "goBack");
-                            });
-                        }
-                        _lastPress = ivec2(INT_MIN);
-                    }
-                    return;
-                }
-
-                // FIXME doesn't work... double click events not received
-                if (event->type() == QEvent::MouseButtonDblClick) {
-                    AbstractViewStateInterface::instance()->postLambdaEvent([this] {
-                        _webSurface->getRootItem()->setProperty("url", _sourceUrl);
-                    });
-                }
-
-                if (event->button() == Qt::MouseButton::MiddleButton) {
-                    if (event->type() == QEvent::MouseButtonRelease) {
-                        AbstractViewStateInterface::instance()->postLambdaEvent([this] {
-                            _webSurface->getRootItem()->setProperty("url", _sourceUrl);
-                        });
-                    }
-                    return;
-                }
-
-                // Map the intersection point to an actual offscreen pixel
-                glm::vec3 point = intersection.intersection;
-                point -= getPosition();
-                point = glm::inverse(getRotation()) * point;
-                point /= getDimensions();
-                point += 0.5f;
-                point.y = 1.0f - point.y;
-                point *= getDimensions() * METERS_TO_INCHES * DPI;
-
-                if (event->button() == Qt::MouseButton::LeftButton) {
-                    if (event->type() == QEvent::MouseButtonPress) {
-                        this->_pressed = true;
-                        this->_lastMove = ivec2((int)point.x, (int)point.y);
-                    } else if (event->type() == QEvent::MouseButtonRelease) {
-                        this->_pressed = false;
-                    }
-                }
-                if (event->type() == QEvent::MouseMove) {
-                    this->_lastMove = ivec2((int)point.x, (int)point.y);
-                }
-
-                // Forward the mouse event.  
-                QMouseEvent mappedEvent(event->type(),
-                    QPoint((int)point.x, (int)point.y),
-                    event->screenPos(), event->button(),
-                    event->buttons(), event->modifiers());
-                QCoreApplication::sendEvent(_webSurface->getWindow(), &mappedEvent);
-            }
-        };
-
-        EntityTreeRenderer* renderer = static_cast<EntityTreeRenderer*>(args->_renderer);
-        _mousePressConnection = QObject::connect(renderer, &EntityTreeRenderer::mousePressOnEntity, forwardMouseEvent);
-        _mouseReleaseConnection = QObject::connect(renderer, &EntityTreeRenderer::mouseReleaseOnEntity, forwardMouseEvent);
-        _mouseMoveConnection = QObject::connect(renderer, &EntityTreeRenderer::mouseMoveOnEntity, forwardMouseEvent);
-        _hoverLeaveConnection = QObject::connect(renderer, &EntityTreeRenderer::hoverLeaveEntity, [=](const EntityItemID& entityItemID, const MouseEvent& event) {
-            if (this->_pressed && this->getID() == entityItemID) {
-                // If the user mouses off the entity while the button is down, simulate a mouse release
-                QMouseEvent mappedEvent(QEvent::MouseButtonRelease, 
-                    QPoint(_lastMove.x, _lastMove.y), 
-                    Qt::MouseButton::LeftButton, 
-                    Qt::MouseButtons(), Qt::KeyboardModifiers());
-                QCoreApplication::sendEvent(_webSurface->getWindow(), &mappedEvent);
-            }
-        });
+        if (!buildWebSurface(static_cast<EntityTreeRenderer*>(args->_renderer))) {
+            return;
+        }
     }
 
+    _lastRenderTime = usecTimestampNow();
     glm::vec2 dims = glm::vec2(getDimensions());
     dims *= METERS_TO_INCHES * DPI;
     // The offscreen surface is idempotent for resizes (bails early
     // if it's a no-op), so it's safe to just call resize every frame 
     // without worrying about excessive overhead.
     _webSurface->resize(QSize(dims.x, dims.y));
-    currentContext->makeCurrent(currentSurface);
 
     PerformanceTimer perfTimer("RenderableWebEntityItem::render");
     Q_ASSERT(getType() == EntityTypes::Web);
@@ -223,3 +226,37 @@ void RenderableWebEntityItem::setProxyWindow(QWindow* proxyWindow) {
 QObject* RenderableWebEntityItem::getEventHandler() {
     return _webSurface->getEventHandler();
 }
+
+void RenderableWebEntityItem::destroyWebSurface() {
+    if (_webSurface) {
+        --_currentWebCount;
+        _webSurface->pause();
+        _webSurface->disconnect(_connection);
+        QObject::disconnect(_mousePressConnection);
+        _mousePressConnection = QMetaObject::Connection();
+        QObject::disconnect(_mouseReleaseConnection);
+        _mouseReleaseConnection = QMetaObject::Connection();
+        QObject::disconnect(_mouseMoveConnection);
+        _mouseMoveConnection = QMetaObject::Connection();
+        QObject::disconnect(_hoverLeaveConnection);
+        _hoverLeaveConnection = QMetaObject::Connection();
+
+        // The lifetime of the QML surface MUST be managed by the main thread
+        // Additionally, we MUST use local variables copied by value, rather than
+        // member variables, since they would implicitly refer to a this that 
+        // is no longer valid
+        auto webSurface = _webSurface;
+        AbstractViewStateInterface::instance()->postLambdaEvent([webSurface] {
+            webSurface->deleteLater();
+        });
+        _webSurface = nullptr;
+    }
+}
+
+
+void RenderableWebEntityItem::update(const quint64& now) {
+    auto interval = now - _lastRenderTime;
+    if (interval > MAX_NO_RENDER_INTERVAL) {
+        destroyWebSurface();
+    }
+}
diff --git a/libraries/entities-renderer/src/RenderableWebEntityItem.h b/libraries/entities-renderer/src/RenderableWebEntityItem.h
index da1ddbf1a1..49a55b6b27 100644
--- a/libraries/entities-renderer/src/RenderableWebEntityItem.h
+++ b/libraries/entities-renderer/src/RenderableWebEntityItem.h
@@ -18,6 +18,7 @@
 class OffscreenQmlSurface;
 class QWindow;
 class QObject;
+class EntityTreeRenderer;
 
 class RenderableWebEntityItem : public WebEntityItem  {
 public:
@@ -31,15 +32,22 @@ public:
     void setProxyWindow(QWindow* proxyWindow);
     QObject* getEventHandler();
 
+    void update(const quint64& now) override;
+    bool needsToCallUpdate() const { return _webSurface != nullptr; }
+
     SIMPLE_RENDERABLE();
 
 private:
+    bool buildWebSurface(EntityTreeRenderer* renderer);
+    void destroyWebSurface();
+
     OffscreenQmlSurface* _webSurface{ nullptr };
     QMetaObject::Connection _connection;
     uint32_t _texture{ 0 };
     ivec2  _lastPress{ INT_MIN };
     bool _pressed{ false };
     ivec2 _lastMove{ INT_MIN };
+    uint64_t _lastRenderTime{ 0 };
 
     QMetaObject::Connection _mousePressConnection;
     QMetaObject::Connection _mouseReleaseConnection;
diff --git a/libraries/entities/src/ParticleEffectEntityItem.cpp b/libraries/entities/src/ParticleEffectEntityItem.cpp
index 16196aa129..4b798cbcd9 100644
--- a/libraries/entities/src/ParticleEffectEntityItem.cpp
+++ b/libraries/entities/src/ParticleEffectEntityItem.cpp
@@ -103,6 +103,7 @@ EntityItemPointer ParticleEffectEntityItem::factory(const EntityItemID& entityID
 // our non-pure virtual subclass for now...
 ParticleEffectEntityItem::ParticleEffectEntityItem(const EntityItemID& entityItemID) :
     EntityItem(entityItemID),
+    _previousPosition(getPosition()),
     _lastSimulated(usecTimestampNow())
 {
     _type = EntityTypes::ParticleEffect;
@@ -623,7 +624,8 @@ void ParticleEffectEntityItem::stepSimulation(float deltaTime) {
             }
             
             // emit a new particle at tail index.
-            _particles.push_back(createParticle());
+            _particles.push_back(createParticle(glm::mix(_previousPosition, getPosition(),
+                (deltaTime - timeLeftInFrame) / deltaTime)));
             auto particle = _particles.back();
             particle.lifetime += timeLeftInFrame;
             
@@ -637,15 +639,16 @@ void ParticleEffectEntityItem::stepSimulation(float deltaTime) {
 
         _timeUntilNextEmit -= timeLeftInFrame;
     }
+    _previousPosition = getPosition();
 }
 
-ParticleEffectEntityItem::Particle ParticleEffectEntityItem::createParticle() {
+ParticleEffectEntityItem::Particle ParticleEffectEntityItem::createParticle(const glm::vec3& position) {
     Particle particle;
 
  
     particle.seed = randFloatInRange(-1.0f, 1.0f);
     if (getEmitterShouldTrail()) {
-        particle.position = getPosition();
+        particle.position = position;
     }
     // Position, velocity, and acceleration
     if (_polarStart == 0.0f && _polarFinish == 0.0f && _emitDimensions.z == 0.0f) {
diff --git a/libraries/entities/src/ParticleEffectEntityItem.h b/libraries/entities/src/ParticleEffectEntityItem.h
index 5afcbe2ae1..ba6f32b51f 100644
--- a/libraries/entities/src/ParticleEffectEntityItem.h
+++ b/libraries/entities/src/ParticleEffectEntityItem.h
@@ -227,7 +227,7 @@ protected:
 
     bool isAnimatingSomething() const;
     
-    Particle createParticle();
+    Particle createParticle(const glm::vec3& position);
     void stepSimulation(float deltaTime);
     void integrateParticle(Particle& particle, float deltaTime);
     
@@ -275,7 +275,7 @@ protected:
     float _azimuthStart = DEFAULT_AZIMUTH_START;
     float _azimuthFinish = DEFAULT_AZIMUTH_FINISH;
     
-
+    glm::vec3 _previousPosition;
     quint64 _lastSimulated { 0 };
     bool _isEmitting { true };
 
diff --git a/libraries/gl/src/gl/OffscreenQmlSurface.cpp b/libraries/gl/src/gl/OffscreenQmlSurface.cpp
index 42eea08057..e22feb694d 100644
--- a/libraries/gl/src/gl/OffscreenQmlSurface.cpp
+++ b/libraries/gl/src/gl/OffscreenQmlSurface.cpp
@@ -175,6 +175,7 @@ private:
         doneCurrent();
 
         getContextObject()->moveToThread(QCoreApplication::instance()->thread());
+        _thread.quit();
         _cond.wakeOne();
     }
 
@@ -228,7 +229,7 @@ private:
 
         _quickWindow->setRenderTarget(GetName(*_fbo), QSize(_size.x, _size.y));
 
-        {
+        try {
             PROFILE_RANGE("qml_render")
             TexturePtr texture = _textures.getNextTexture();
             _fbo->Bind(Framebuffer::Target::Draw);
@@ -245,8 +246,10 @@ private:
             DefaultFramebuffer().Bind(Framebuffer::Target::Draw);
             _quickWindow->resetOpenGLState();
             _escrow.submit(GetName(*texture));
+            _lastRenderTime = usecTimestampNow();
+        } catch (std::runtime_error& error) {
+            qWarning() << "Failed to render QML " << error.what();
         }
-        _lastRenderTime = usecTimestampNow();
     }
 
     void aboutToQuit() {
@@ -321,7 +324,7 @@ OffscreenQmlSurface::~OffscreenQmlSurface() {
 
 void OffscreenQmlSurface::create(QOpenGLContext* shareContext) {
     _renderer = new OffscreenQmlRenderer(this, shareContext);
-
+    _renderer->_renderControl->_renderWindow = _proxyWindow;
     // Create a QML engine.
     _qmlEngine = new QQmlEngine;
     if (!_qmlEngine->incubationController()) {
@@ -610,7 +613,10 @@ bool OffscreenQmlSurface::isPaused() const {
 }
 
 void OffscreenQmlSurface::setProxyWindow(QWindow* window) {
-    _renderer->_renderControl->_renderWindow = window;
+    _proxyWindow = window;
+    if (_renderer && _renderer->_renderControl) {
+        _renderer->_renderControl->_renderWindow = window;
+    }
 }
 
 QObject* OffscreenQmlSurface::getEventHandler() {
diff --git a/libraries/gl/src/gl/OffscreenQmlSurface.h b/libraries/gl/src/gl/OffscreenQmlSurface.h
index 9e3ee06f92..5641d16a30 100644
--- a/libraries/gl/src/gl/OffscreenQmlSurface.h
+++ b/libraries/gl/src/gl/OffscreenQmlSurface.h
@@ -95,7 +95,7 @@ private:
     bool _paused{ true };
     uint8_t _maxFps{ 60 };
     MouseTranslator _mouseTranslator{ [](const QPointF& p) { return p.toPoint();  } };
-
+    QWindow* _proxyWindow { nullptr };
 };
 
 #endif
diff --git a/libraries/physics/src/CharacterController.h b/libraries/physics/src/CharacterController.h
index 5362ca52e4..a8543d6070 100644
--- a/libraries/physics/src/CharacterController.h
+++ b/libraries/physics/src/CharacterController.h
@@ -78,6 +78,8 @@ public:
 
     glm::vec3 getLinearVelocity() const;
 
+    float getCapsuleRadius() const { return _radius; }
+
     enum class State {
         Ground = 0,
         Takeoff,
diff --git a/libraries/render-utils/src/AbstractViewStateInterface.h b/libraries/render-utils/src/AbstractViewStateInterface.h
index 1165816dd2..815cb45423 100644
--- a/libraries/render-utils/src/AbstractViewStateInterface.h
+++ b/libraries/render-utils/src/AbstractViewStateInterface.h
@@ -36,7 +36,7 @@ public:
 
     virtual QThread* getMainThread() = 0;
     
-    virtual PickRay computePickRay(float x, float y) = 0;
+    virtual PickRay computePickRay(float x, float y) const = 0;
 
     virtual glm::vec3 getAvatarPosition() const = 0;
 
diff --git a/libraries/render-utils/src/Model.cpp b/libraries/render-utils/src/Model.cpp
index 91c9ec623d..3b741ac734 100644
--- a/libraries/render-utils/src/Model.cpp
+++ b/libraries/render-utils/src/Model.cpp
@@ -92,15 +92,15 @@ void Model::setScale(const glm::vec3& scale) {
     _scaledToFit = false;
 }
 
-const float METERS_PER_MILLIMETER = 0.01f; 
+const float SCALE_CHANGE_EPSILON = 0.01f;
 
 void Model::setScaleInternal(const glm::vec3& scale) {
-    if (glm::distance(_scale, scale) > METERS_PER_MILLIMETER) {
+    if (glm::distance(_scale, scale) > SCALE_CHANGE_EPSILON) {
         _scale = scale;
         if (_scale.x == 0.0f || _scale.y == 0.0f || _scale.z == 0.0f) {
             assert(false);
         }
-        initJointTransforms();
+        simulate(0.0f, true);
     }
 }
 
diff --git a/libraries/script-engine/src/AudioScriptingInterface.cpp b/libraries/script-engine/src/AudioScriptingInterface.cpp
index a660e918a9..7e7ca77b88 100644
--- a/libraries/script-engine/src/AudioScriptingInterface.cpp
+++ b/libraries/script-engine/src/AudioScriptingInterface.cpp
@@ -45,8 +45,11 @@ ScriptAudioInjector* AudioScriptingInterface::playSound(Sound* sound, const Audi
         // stereo option isn't set from script, this comes from sound metadata or filename
         AudioInjectorOptions optionsCopy = injectorOptions;
         optionsCopy.stereo = sound->isStereo();
-
-        return new ScriptAudioInjector(AudioInjector::playSound(sound->getByteArray(), optionsCopy, _localAudioInterface));
+        auto injector = AudioInjector::playSound(sound->getByteArray(), optionsCopy, _localAudioInterface);
+        if (!injector) {
+            return NULL;
+        }
+        return new ScriptAudioInjector(injector);
 
     } else {
         qCDebug(scriptengine) << "AudioScriptingInterface::playSound called with null Sound object.";
diff --git a/plugins/openvr/src/OpenVrDisplayPlugin.cpp b/plugins/openvr/src/OpenVrDisplayPlugin.cpp
index 7575cc83e7..efd230bc28 100644
--- a/plugins/openvr/src/OpenVrDisplayPlugin.cpp
+++ b/plugins/openvr/src/OpenVrDisplayPlugin.cpp
@@ -30,7 +30,6 @@ const QString OpenVrDisplayPlugin::NAME("OpenVR (Vive)");
 const QString StandingHMDSensorMode = "Standing HMD Sensor Mode"; // this probably shouldn't be hardcoded here
 
 static vr::IVRCompositor* _compositor{ nullptr };
-static vr::TrackedDevicePose_t _presentThreadTrackedDevicePose[vr::k_unMaxTrackedDeviceCount];
 vr::TrackedDevicePose_t _trackedDevicePose[vr::k_unMaxTrackedDeviceCount];
 mat4 _trackedDevicePoseMat4[vr::k_unMaxTrackedDeviceCount];
 static mat4 _sensorResetMat;
@@ -43,12 +42,12 @@ bool OpenVrDisplayPlugin::isSupported() const {
 void OpenVrDisplayPlugin::activate() {
     _container->setIsOptionChecked(StandingHMDSensorMode, true);
 
-    if (!_hmd) {
-        _hmd = acquireOpenVrSystem();
+    if (!_system) {
+        _system = acquireOpenVrSystem();
     }
-    Q_ASSERT(_hmd);
+    Q_ASSERT(_system);
 
-    _hmd->GetRecommendedRenderTargetSize(&_renderTargetSize.x, &_renderTargetSize.y);
+    _system->GetRecommendedRenderTargetSize(&_renderTargetSize.x, &_renderTargetSize.y);
     // Recommended render target size is per-eye, so double the X size for 
     // left + right eyes
     _renderTargetSize.x *= 2;
@@ -56,8 +55,8 @@ void OpenVrDisplayPlugin::activate() {
     {
         Lock lock(_poseMutex);
         openvr_for_each_eye([&](vr::Hmd_Eye eye) {
-            _eyeOffsets[eye] = toGlm(_hmd->GetEyeToHeadTransform(eye));
-            _eyeProjections[eye] = toGlm(_hmd->GetProjectionMatrix(eye, DEFAULT_NEAR_CLIP, DEFAULT_FAR_CLIP, vr::API_OpenGL));
+            _eyeOffsets[eye] = toGlm(_system->GetEyeToHeadTransform(eye));
+            _eyeProjections[eye] = toGlm(_system->GetProjectionMatrix(eye, DEFAULT_NEAR_CLIP, DEFAULT_FAR_CLIP, vr::API_OpenGL));
         });
         // FIXME Calculate the proper combined projection by using GetProjectionRaw values from both eyes
         _cullingProjection = _eyeProjections[0];
@@ -71,9 +70,9 @@ void OpenVrDisplayPlugin::activate() {
 
 void OpenVrDisplayPlugin::deactivate() {
     _container->setIsOptionChecked(StandingHMDSensorMode, false);
-    if (_hmd) {
+    if (_system) {
         releaseOpenVrSystem();
-        _hmd = nullptr;
+        _system = nullptr;
     }
     _compositor = nullptr;
     HmdDisplayPlugin::deactivate();
@@ -96,9 +95,31 @@ void OpenVrDisplayPlugin::resetSensors() {
     _sensorResetMat = glm::inverse(cancelOutRollAndPitch(m));
 }
 
-
 glm::mat4 OpenVrDisplayPlugin::getHeadPose(uint32_t frameIndex) const {
-    Lock lock(_poseMutex);
+
+    float displayFrequency = _system->GetFloatTrackedDeviceProperty(vr::k_unTrackedDeviceIndex_Hmd, vr::Prop_DisplayFrequency_Float);
+    float frameDuration = 1.f / displayFrequency;
+    float vsyncToPhotons = _system->GetFloatTrackedDeviceProperty(vr::k_unTrackedDeviceIndex_Hmd, vr::Prop_SecondsFromVsyncToPhotons_Float);
+
+#if THREADED_PRESENT
+    // TODO: this seems awfuly long, 44ms total, but it produced the best results.
+    const float NUM_PREDICTION_FRAMES = 3.0f;
+    float predictedSecondsFromNow = NUM_PREDICTION_FRAMES * frameDuration + vsyncToPhotons;
+#else
+    uint64_t frameCounter;
+    float timeSinceLastVsync;
+    _system->GetTimeSinceLastVsync(&timeSinceLastVsync, &frameCounter);
+    float predictedSecondsFromNow = 3.0f * frameDuration - timeSinceLastVsync + vsyncToPhotons;
+#endif
+
+    vr::TrackedDevicePose_t predictedTrackedDevicePose[vr::k_unMaxTrackedDeviceCount];
+    _system->GetDeviceToAbsoluteTrackingPose(vr::TrackingUniverseSeated, predictedSecondsFromNow, predictedTrackedDevicePose, vr::k_unMaxTrackedDeviceCount);
+
+    // copy and process predictedTrackedDevicePoses
+    for (int i = 0; i < vr::k_unMaxTrackedDeviceCount; i++) {
+        _trackedDevicePose[i] = predictedTrackedDevicePose[i];
+        _trackedDevicePoseMat4[i] = _sensorResetMat * toGlm(_trackedDevicePose[i].mDeviceToAbsoluteTracking);
+    }
     return _trackedDevicePoseMat4[0];
 }
 
@@ -112,18 +133,8 @@ void OpenVrDisplayPlugin::internalPresent() {
     _compositor->Submit(vr::Eye_Left, &texture, &leftBounds);
     _compositor->Submit(vr::Eye_Right, &texture, &rightBounds);
 
-    glFinish();
-
-    _compositor->WaitGetPoses(_presentThreadTrackedDevicePose, vr::k_unMaxTrackedDeviceCount, nullptr, 0);
-
-    {
-        // copy and process _presentThreadTrackedDevicePoses
-        Lock lock(_poseMutex);
-        for (int i = 0; i < vr::k_unMaxTrackedDeviceCount; i++) {
-            _trackedDevicePose[i] = _presentThreadTrackedDevicePose[i];
-            _trackedDevicePoseMat4[i] = _sensorResetMat * toGlm(_trackedDevicePose[i].mDeviceToAbsoluteTracking);
-        }
-    }
+    vr::TrackedDevicePose_t currentTrackedDevicePose[vr::k_unMaxTrackedDeviceCount];
+    _compositor->WaitGetPoses(currentTrackedDevicePose, vr::k_unMaxTrackedDeviceCount, nullptr, 0);
 
     // Handle the mirroring in the base class
     HmdDisplayPlugin::internalPresent();
diff --git a/plugins/openvr/src/OpenVrDisplayPlugin.h b/plugins/openvr/src/OpenVrDisplayPlugin.h
index 9c480e48f7..4344c3c48f 100644
--- a/plugins/openvr/src/OpenVrDisplayPlugin.h
+++ b/plugins/openvr/src/OpenVrDisplayPlugin.h
@@ -35,7 +35,7 @@ protected:
     virtual void internalPresent() override;
 
 private:
-    vr::IVRSystem* _hmd { nullptr };
+    vr::IVRSystem* _system { nullptr };
     static const QString NAME;
     mutable Mutex _poseMutex;
 };